7NQ4
Human tRNA guanine transglycosylase (TGT), RNA-bound covalent intermediate
Summary for 7NQ4
| Entry DOI | 10.2210/pdb7nq4/pdb |
| Descriptor | Queuine tRNA-ribosyltransferase catalytic subunit 1, Queuine tRNA-ribosyltransferase accessory subunit 2, RNA, ... (6 entities in total) |
| Functional Keywords | trna modification, queuine incorporation, rna complex, heterodimer, rna binding protein |
| Biological source | Homo sapiens (Human) More |
| Total number of polymer chains | 3 |
| Total formula weight | 97730.30 |
| Authors | Sievers, K.,Ficner, R. (deposition date: 2021-03-01, release date: 2021-08-11, Last modification date: 2024-01-31) |
| Primary citation | Sievers, K.,Welp, L.,Urlaub, H.,Ficner, R. Structural and functional insights into human tRNA guanine transgylcosylase. Rna Biol., 18:382-396, 2021 Cited by PubMed Abstract: The eukaryotic tRNA guanine transglycosylase (TGT) is an RNA modifying enzyme incorporating queuine, a hypermodified guanine derivative, into the tRNAs. While both subunits of the functional heterodimer have been crystallized individually, much of our understanding of its dimer interface or recognition of a target RNA has been inferred from its more thoroughly studied bacterial homolog. However, since bacterial TGT, by incorporating queuine precursor preQ, deviates not only in function, but as a homodimer, also in its subunit architecture, any inferences regarding the subunit association of the eukaryotic heterodimer or the significance of its unique catalytically inactive subunit are based on unstable footing. Here, we report the crystal structure of human TGT in its heterodimeric form and in complex with a 25-mer stem loop RNA, enabling detailed analysis of its dimer interface and interaction with a minimal substrate RNA. Based on a model of bound tRNA, we addressed a potential functional role of the catalytically inactive subunit QTRT2 by UV-crosslinking and mutagenesis experiments, identifying the two-stranded βEβF-sheet of the QTRT2 subunit as an additional RNA-binding motif. PubMed: 34241577DOI: 10.1080/15476286.2021.1950980 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.88 Å) |
Structure validation
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